Biblio

Nowadays, smart contracts manage more and more digital assets and have become an attractive target for adversaries. To prevent smart contracts from malicious attacks, a thorough test is indispensable and must be finished before deployment because smart contracts cannot be modified after being deployed. Fuzzing is an important testing approach, but most existing smart contract fuzzers can hardly solve the constraints which involve deeply nested conditional statements, resulting in low coverage. To address this problem, we propose Targy, an efficient targeted mutation strategy based on dynamic taint analysis. We obtain the taint flow by dynamic taint propagation, and generate a more accurate mutation strategy for the input parameters of functions to simultaneously satisfy all conditional statements. We implemented Targy on sFuzz with 3.6 thousand smart contracts running on Ethereum. The numbers of covered branches and detected vulnerabilities increase by 6% and 7% respectively, and the average time required for covering a branch is reduced by 11 %.

With the increasing deployment of enterprise-scale distributed systems, effective and practical defenses for such systems against various security vulnerabilities such as sensitive data leaks are urgently needed. However, most existing solutions are limited to centralized programs. For real-world distributed systems which are of large scales, current solutions commonly face one or more of scalability, applicability, and portability challenges. To overcome these challenges, we develop a novel dynamic taint analysis for enterprise-scale distributed systems. To achieve scalability, we use a multi-phase analysis strategy to reduce the overall cost. We infer implicit dependencies via partial-ordering method events in distributed programs to address the applicability challenge. To achieve greater portability, the analysis is designed to work at an application level without customizing platforms. Empirical results have shown promising scalability and capabilities of our approach.

Dynamic taint analysis is a program analysis technique in which data is marked and its propagation is tracked while the program is executing. It is applied to solve problems in many fields, especially in software security. Current taint analysis platforms are limited to a single programming language, and therefore cannot support programs which, as is common today, are implemented in multiple programming languages. Current implementations of dynamic taint analysis also incur a significant performance overhead. In this paper we address both these limitations (1) by presenting our vision of a multi-language dynamic taint analysis platform, which is built around a language-agnostic core framework that is extended by language-specific front-ends and (2) by discussing the use of speculative optimization and dynamic compilation to reduce the execution overhead of dynamic taint analysis applications. An implementation of such a platform would enable dynamic taint analyses that can target multiple languages in one analysis implementation and can track tainted data across language boundaries. We describe this approach in the context of the GraalVM runtime and its included JIT compiler, Graal, which allows us to target both dynamic and static languages.

Dynamic Taint Analysis (DTA) technique has been developed for analysis and understanding behavior of Android applications and privacy policy enforcement. Meanwhile, implicit information flows (IIFs) are major concern of security researchers because IIFs can evade DTA technique easily and give attackers an advantage over the researchers. Some researchers suggested approaches to the issue and developed analysis systems supporting privacy policy enforcement against IIF-accompanied attacks; however, there is still no effective technique of comprehensive analysis and privacy policy enforcement against IIF-accompanied attacks. In this paper, we propose an IIF detection technique to enforce privacy policy against IIF-accompanied attacks in Android applications. We developed a new analysis tool, called Smalien, that can discover data leakage caused by IIF-contained information flows as well as explicit information flows. We demonstrated practicability of Smalien by applying it to 16 IIF tricks from ScrubDroid and two IIF tricks from DroidBench. Smalien enforced privacy policy successfully against all the tricks except one trick because the trick loads code dynamically from a remote server at runtime, and Smalien cannot analyze any code outside of a target application. The results show that our approach can be a solution to the current attacker-superior situation.

Android smartphones are ubiquitous all over the world, and organizations that turn profits out of data mining user personal information are on the rise. Many users are not aware of the risks of accepting permissions from Android apps, and the continued state of insecurity, manifested in increased level of breaches across all large organizations means that personal information is falling in the hands of malicious actors. This paper aims at shedding the light on privacy leakage in apps that target a specific demography, Arabs. The research takes into consideration apps that cater to specific cultural aspects of this region and identify how they could be abusing the trust given to them by unsuspecting users. Dynamic taint analysis is used in a virtualized environment to analyze top free apps based on popularity in Google Play store. Information presented highlights how different categories of apps leak different categories of private information.